Needle valve



Jan. 28, 1941. K. TATE ETAL NEEDLE VALVE F iled Jan. 30, 1940 INVENTOR. KENNETH L. TATE AND y R5040 DA.KEBERLE7 Patented Jan. 28, 1941 UNITED STATES PATENT OFFKIE ester, N. Y., assignors to Taylor Instrument Companies, Rochester, N. Y., a corporation of New York Application January 30, 1940, Serial No. 316,378

2 Claims.

This invention relates to valves and more particularly to needle valves.

In the past, needle valves have been opened and closed by a rotary adjustment of the valve 5 needle with respect to the valve seat. This rotation of the valve needle has resulted in scoring either the needle or its seat, or both, so that the valve soon became worn. It has been found in practice that when needle valves are used to regulate the flow of fluid, such as air, therethrough, it was not possible to repeat a given rate of flow except by the cut-and-try adjustments of the valve. However, in certain types of pneumatically operated controllers it is important that the needle valve or the like be adjustable to various positions with reference to a graduated scale which indicates for each valve setting, the amount of controlling fluid flowing therethrough in a given interval.

The main feature of the present invention relates to a needle valve of such construction that the adjustment of the valve does not result either in the scoring of the valve seat or the valve needle.

Another feature of the invention relates to the construction of a needle valve in which a given adjustment of the valve needle always results in substantially the same amount of Valve opening so that there is an invariable amount of fluid flowing through the valve per unit of time, for each valve adjustment.

A further feature of the invention relates to a needle valve construction in which the needle assembly can be removed for cleaning and then replaced without changing the valve setting.

The various features and advantages of the invention will appear from the detailed description and claims when taken with the drawing in which Fig. 1 is an enlarged vertical section taken through the valve and Fig. 2 is a bottom view of the orifice disk and a cross-section through the valve needle taken on the line 22 of Fig. 1.

The needle valve of the present invention comprises a valve body 5 having a central bore 6 therethrough. The lower end of the valve body as illustrated in Fig. 1 is recessed about the central bore to provide an annular shoulder I. The recess is substantially closed by an orifice disk 8 which is joined in air-tight relation to the valve body by means of solder or the like. The orifice 9 in the disk is tapered to provide a generally conical seat. The valve body at an intermediate portion of the bore is internally threaded to make threaded engagement with a stem l0 provided with external threads adjacent its lower end to engage the internal threads of the body. The upper portion of the central bore is somewhat enlarged to provide a seat ll against which stuffing material [2 engages to prevent leakage between the stem and the body. A gland nut l3 having a central'bore therethrough to receive the stem l0, makes threaded engagement with the upper portion of the valve body as'indicated and functions to compress the stuffing material I2 against the seat H. The upper end of the stem 1 I0 is provided with a hand wheel H1 or any other means by which the stem can be rotated with respect to the valve body. The lower end of the stem is provided with a portion of reduced diameter and terminates in an end l5 which is bevele or inclined with respect to the principal axis of the stem. The valve body together with the orifice disk 8 and the lower end of the stem I0 define a chamber. This chamber communicates through a passage 2| with an inlet connectible to 20 a source of compressed air or like fluid, the fiow of which is to be controlled by the valve.

It has been mentioned that the orifice plate 8 is provided with a conical bore therethrough serving as a conical valve seat. A valve needle I6, having an end portion of the same taper as that of the valve seat and terminating in a spherical surface, extends through the bore in the disk 8 with its free spherical end engaging the beveled end l5 of the stem. By this arrangement the valve needle in its partially opened position is forced by the beveled end of the stem into eccentric relation with respect to the valve seat and engages one side thereof. The valve needle is preferably spring biased so that its spherical end portion always engages the beveled end of the stem [5 while the valve is open. A convenient way of achieving this biasing action is by providing a cap l1 having its rim internally threaded to engage the threaded end portion of the valve 40 body. The lower end of the cap as shown in Fig. 1 has an aperture therethrough generally in alinement with the bore through the valve body, to receive the lower end of the valve needle.

An intermediate portion of the valve needle is provided with a shoulder l8 against which one end of a helical spring l9 engages, the other end of this spring engaging the inner surface of the cap I'I. Thus the mentioned spring tends to urge the valve needle in a direction to close the open- 50 ing in the orifice disk. The extreme lower end of the valve needle is provided with a shoulder 20 to engage the outer surface of the cap and thereby limit the upward movement of the valve needle (Fig. 1) when the cap 11 is disengaged assume various positions laterally with respect to the orifice disk, the passage therethroughr may vary from a true annular shape to a crescent shape. Under these last-mentioned conditions the flow of fluid through the. valve willi inot be the same even when the valve needle? has the same longitudinal relation to the valve body,

due to the possible variable-lateral relatiombe I tween these parts. However, in the arrangement of the present invention, where the needle inits partially open condition is always maintained in eccentric relation withrrespect to, said orifice and'in engagement With a side. wall'thereoflthe openingv through the orifice is always crescentshaped'andlthe fluid flow throughith-e orifice is alwaysthe same forany given adjustment of the stem..

It will be appreciated that when the stem I'B is. adjustedby rotatingit in one direction it will vmove longitudinally towardlthe' disk and. the inclined end, of the, stem will force the needle downward (Fig. 1) against the action of the spring to open the valve. When the stem is adjusted by rotating it in the opposite direction; it recedes from the disk, permitting, the. spring to forcethe' needle into the orifice to close. As. a result. of each adjustment the inclined end of the.st'em..tends to force the needle into eccentric relation to the orificeso that the opening therethrough isvalways crescent-shaped; In the present inventionthe valve needle is never rotated during. adjustment and consequently there isrno possible .scoringjof the valve parts. Since the cap. IT with the valve needle assembled thereon, can be removed'from the body 5 without changing the adjustment of the stem ID, the valve. needle assembly can be removed for clean.- ing and. then replaced without disturbing. the valve setting.

We1.claiin:

lLI'n. a device of the class described, a. valve body having, a bore therethrough, an orifice disc extending across said bore, said disc having its peripheral margin in fluid-tight relation with the wall of said bore, said disc having an orifice therethrough defining a tapered valve seat, a longitudinally adjustable stem extending into said bare with an end thereof positioned adjacent one side of said disc, said end being flat and inclined with respect to the principal axis of said stem, means for sealing. said" stem in fluid-tight: but adjustable relation to the wall of said bore at a point spaced from said disc, said valve body having a passage therethrough leading to said disc at the side thereof adjacent said" stem, a tapered valve needle projecting through the orifice in said disc for closing the same; meansqnormally forcing said needle longitudinally, with its end in engagement with the inclined fiat -end of said stem, whereby said valve needle is moved longitudinally and laterally in eccentric relation with respect to said orifice and.

into:' engagement with the wall of said orifice when saidvalve stem is.adjustedlongitudinally.

2; In a device of the classndescribed; at valve body having a bore therethrough, an orifice disc extending, across saidibore, said'disc. having its peripheral margin in fluid-tight relation with thewall'of said bore,rsaid disc having an orifice therethrough definng a tapered valve seat; a longitudinally adjustable stem extending into sai'dibore with an end thereof positioned adjacent one side of said" disc,

of said stem, means for sealing said stemin fluid-tight adjustable relation to the wall of said.

bore at a pointLspaced from said disc, said valve body having, a passage therethrough leading. to said disc at the side thereof adjacent said stem, a. member detachably secured to said valve body at the other side of said disc, a valve needle slide ably carried-by said member, a portion of said valve needle being tapered to correspond to said tapered'valve seat and terminating, in a free. end, said tapered portion of'said valve needle projecting through the orifice in said discf'on' closing the same, means carried by said member normally forcing said needle longitudinally with its free end in engagementwith the inclinedend of said stem whereby said valve needlev is moved longitudinally andv laterally in eccentric relation with respect tosaid orifice and into engagement withv the, wall of said orifice when said valve'stem is adjusted longitudinally.

KENNETH L. TATE.'. RAYMOND A. KEBERLE.

said end being. fiat. and" inclined with respect to the principal axis. 

